"We do not believe this is related to a terrorist incident at all but we are not ruling that out because it is early," Perez said.

The shooting comes as many travelers are trying to get out of the path of the Category 5 hurricane, which devastated a string of Caribbean islands and is on its way to Florida.Shawn Woodford and his wife were about to board a flight home for Canada when fire trucks and police cars came "flying across the tarmac" and "surrounded a plane at the gate next to us," he told The Associated Press.

The plane the gate Woodford identified was a Latam Airlines flight to Santiago, Chile, according to Miami's departures board. Latam officials did not immediately respond to a request for comment from the Associated Press.

A short time later, police came into the terminal where Woodford and his wife were and "said 'everybody out of here' and evacuated the entire concourse," he said.

Woodford said the majority of the flights in the terminal were international flights.

It was not immediately clear how the closure was affecting flights. Miami's airport departures notifications showed several delays for flights at J gates. But Woodford was able to board his flight for Toronto—at a different concourse and nearly 4 hours after his original departure time.

The Latam flight to Santiago was listed as delayed nearly two hours, but still leaving at midnight.